The invention relates to the technical field of in-situ leaching uranium mining, in particular to a multi-layer sandstone type uranium mine slicing mining process to solve the problems that existing processes are high in cost and low in efficiency, and raw materials are prone to being wasted. The multi-layer sandstone type uranium mine slicing mining process comprises the steps of liquid injection and suction hole construction, earth surface liquid separation control system implementation, downhole liquid separation control system implementation and liquid suction and injection unit slicing operation. Through the multi-layer sandstone type uranium mine slicing mining process, a suction and injection circulation unit that multi-layer mine bodies share a liquid injection hole and correspond to liquid suction holes in all layers is formed, simultaneous mining of multi-layer mine bodies is achieved, and the drilling cost of multi-layer sandstone type uranium mine in-situ leaching mining is greatly reduced.